This invention concerns a plug-in connector suitable for use in a liquid medium such as water.
Plug-in connectors suitable for use under water are known in the prior art and described, for example, in U.S. Pat. Nos. 3,508,188, 3,585,567, 3,772,636, 3,845,450, 3,877,775 and 4,039,242.
These connectors make use of movable parts which cover electrical contacts when the two elements forming the connector are separated, and which are automatically pushed back, into a housing provided therefor when the two elements of the connector are assembled. An insulating liquid such as an oil in equipressure relationship with the external medium, completes the protection of the electric contacts and prevents penetration of water into the connector.
Such connectors may give satisfactory results but are expensive and fragile because-therefor of their movable parts. In addition, they require good sealing to limit any leakage of the insulating liquid.
In order to obviate these drawbacks, other connectors have been built which comprise a socket and a complementary plug, the latter being adapted to push back an insulating material of high viscosity into a chamber in equipressure relationship with the external medium. When the plug is withdrawn from the socket, the space left free is automatically filled with the insulating material. The chamber of insulating material generally comprises a deformable wall consisting, for example, of a flexible membrane.
The problem to be solved is then to make use of a minimum amount of insulating product and, accordingly, to ensure a good transfer of said insulating product between the chamber and the space left free by the plug withdrawal.